Suction valve for rotary compressor

ABSTRACT

A suction valve having a chamber including an outlet communicating with the suction port of a rotary compressor, an inlet for receiving a flow of gas, a valve holding area having a film of liquid arranged opposite the inlet and a valve movable between the inlet and the holding area. The liquid has a viscosity sufficient to create a surface tension which will maintain the valve in the holding area during the flow of gas and to permit the valve to break the surface tension a predetermined time after the termination of the gas flow.

ate 1 1 1 Ladusaw 1 SUCTION VALVE FOR ROTARY COMPRESSOR [75] Inventor:William T. Ladusaw, Louisville, Ky.

[73] Assignee: General Electric Company,

Louisville, Ky.

[22] Filed: Apr. 29, 1974 [21] App]. No.: 464,893

Related US. Application Data [63] Continuation-in-part of Ser. No.373.188, June 25,

1973, abandoned.

[52] US. Cl 418/63; 137/513.11 [51] Int. Cl. ..F01c 1/02 [58] Field ofSearch. 418/63; 137/2, 519.5, 533.13,

[56] References Cited UNITED STATES PATENTS 1,543,163 6/1925 Johnson eta1 418/63 1,989,199 1/1935 Hummert 137/533.13 2,278,715 4/1942 Stoyke eta1. l37/533.13

[ June 24, 11975 2,332,787 10/1943 Fleming l37/533.l3 2,395,065 2/1946Rataiczak 418/63 2,591,174 4/1952 Martin 137/533.13 3,105,633 10/1963Dellario 418/63 FOREIGN PATENTS OR APPLICATIONS 131,876 1919 UnitedKingdom Primary ExaminerWil1iam L. Freeh Assistant ExaminerG. P.LaPointe [57] ABSTRACT A suction valve having a chamber including anoutlet communicating with the suction port of a rotary compressor, aninlet for receiving; a flow of gas, a valve holding area having a filmof liquid arranged opposite the inlet and a valve movable between theinlet and the holding area. The liquid has a viscosity sufficient tocreate a surface tension which will maintain the valve in the holdingarea during the flow of gas and to permit the valve to break the surfacetension a predetermined time after the termination of the gas flow.

7 Claims, 6 Drawing Figures JUN24 9 PATENTED 5 SHEET 1 V JBSLBSBPATENTEDJIJM 24 1975 I SHEET W m A V6 I SUCTION VALVE FOR ROTARYCOMPRESSOR CROSS REFERENCE TO RELATED APPLICATION BACKGROUND OF THEINVENTION A well-known type of rotary compressor comprises a cylindricalwall member and end plates defining a compression chamber or cylinder, arotor centrally mounted within the cylinder and a vane slidably mountedwithin the cylindrical wall for engagement with the periphery of therotor to divide the chamber into a high pressure side and a lowerpressure side. In the operation of such compressor, rotation of therotor draws the gas into the low pressure side and discharges thecompressed gas through a discharge port communicating with the highpressure side of the chamber on the opposite side of the vane from thelower pressure port. When such compressor operates intermittently, asfor example, when it forms part of a hermetic refrigeration system,valve means are provided to prevent re verse flow through the suctionport which may take place for example due to the leakage of highpressure gas between the rotor and the cylinder wall to the lowerpressure side and then to the low side of the system when the compressoris stopped. In rotary compressors, including suction port valves, thevalve is normally positioned in the suction passage at a point somewhatremote from the compression chamber and has frequently taken the form ofa simple ball or check valve in the suction passage as shown in US. Pat.No. 3,015,222-Wellborn et al.

When ball check valves have been employed in conjunction with rotarycompressors they have been found to be noisy during operation of thecompressor due to their constant movement in the guide area because ofthe pulsing of the intake gas. This noise generated by a ball valve isundesirable, especially in air conditioning units that are mounted inthe window or wall of an enclosure such as a sleeping area.

SUMMARY OF THE INVENTION A suction valve having a chamber including anoutlet communicating with the suction port of a rotary compressor, aninlet for receiving a pulsing flow of gas, a valve holding means havinga film of liquid, and a valve member disposed in the chamber, beingmovable from the inlet to the holding means by the incoming flow of gasentering the inlet. The surface tension of the liquid between theengaging valve surface and the surface area of the holding means issufficient to maintain the valve in the holding means during the flow ofpulsing gas and to permit the valve to break the surface tension apredetermined time after the termination of the gas flow.

An object of the invention is to provide means responsive to the flow ofrefrigerant gas during operation of the compressor that is effective tohold the valve stationary in an open position and to release the valvein response to the termination of the compressor operation to allow thevalve to return by gravity to its normal closed position.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational viewpartially in crosssection ofa hermetic refrigeration compressorincorporating the present invention;

FIG. 2 is a partial plan view taken along line 2-2 of FIG. 1;

FIG. 3 is a schematic view of a refrigeration system including acompressor of the present invention;

FIG. 4 is an enlarged fragmentary sectional view taken along the line4-4 of FIG. 2;

FIG. 5 is a perspective view of the ball retainer means employed by thepresent invention; and

FIG. 6 is an elevational view in section illustrating a secondembodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, there isshown a hermetic compressor 10 including a hermetic casing 12 in whichthere is disposed a refrigerant compressor unit 14 having an angularchamber or compressor chamber 16 de fined within a cylinder or housing18. Disposed for rotation within the chamber 16 is a rotor 20 which isdriven by an eccentric 22 formed as an integral part of the drive shaft24 extending downwardly from the motor 26. A bearing formed in thesupporting main frame 28, supports the shaft 24 above the eccentric 22for rotation by the motor 26. It should be noted that the upper end wallenclosing the angular compressor chamber 16 is provided by the mainframe 28. The main frame 28 also supports the compressor unit 14 withinthe hermetic casing 12. The opposite or lower end wall 30 of thecompressor chamber 16 also supports the lower end of the shaft 24.

As may best be seen in FIG. 2, the cylinder 18 is provided with a radialslot 32 having slidably disposed therein a blade or vane 34 which isbiased into engagement with the peripheral surface of the rotor 20thereby dividing the chamber '16 into a low and high pressure siderespectively designated as 36 and 38.

As may be seen in FIG. 3, the hermetic compressor 10 is adapted to beconnected into a refrigeration system to receive suction gas from anevaporator 40 through a suction line 42. Means are provided fordelivering the suction gas into the low pressure side 36 of the chamber16 from the suction line 42. More specifically, referring to FIG. 2,these means include chamber or channel 43 having an inlet area 44 formedin the cylinder 18 and communicating with the compressor chamber 16. Theinlet area 44 delivers low pressure gas into the low pressure side of 36of the compression chamber 16 where it is compressed between theperipheral surface of the rotor 20, the sides of the angular chamber 16,and the high pressure side of the vane 34, during rotation of the rotor20 around the chamber.

Means, including a discharge port 46 and discharge chamber 48, areprovided for discharging the high pressure gas from the high pressureside 38 of the angular chamber 16 into the hermetic casing 12. Mountedwithin the discharge chamber 48 is a suitable valve 50 for assuringproper compression of the gas issuing through the discharge port 46 andpreventing reverse flow of gas back into the compression chamber 16. Asmay be seen in FIG. 1, the high pressure gas from the discharge chamber48 flows into the hermetic casing 12 through a passage 52 formed in themain frame 28. After flowing upwardly over the motor 26 the highpressure gas is conducted out of the hermetic casing 12 through asuitable discharge means or outlet in the upper end of the case. The gasthen flows through a discharge line 54 shown only in FIG. 3 into thecondenser 56 where the heat absorbed by the refrigerant in the otherportions of the system is abstracted. As the gas in the condenser 56 iscooled it condenses so that the re frigerant in the latter stage of thecondenser is therefore largely in liquid form.

The present invention is particularly directed to the provision of animproved inlet or suction valve means, generally designated by thenumeral 58, which will seal the compressor inlet or suction port 60 asshown in FIG. 4 in a predetermined minimum amount of time followingtermination of inward refrigerant flow through the compressor inlet 60to avoid or minimize the aforementioned problem of reverse rotation ofthe compressor. To this end, and in accordance with the presentlypreferred form of the present invention, the chamber 43 of thecompressor block 14 is generally vertically arranged between the upperand lower plates. The inlet from the evaporator carrying the refrigerantto the compressor communicates through the lower plate to a valve seat62 formed in said plate. This presently preferred form of the inletvalve means of the present invention includes a ball 64 that is movablymounted within the inlet chamber 43. The ball 64 is made of a size andmass such that, in the absence of inward flow of fluid through thecompressor inlet into the inlet port 60, the ball will move downwardlyby gravity to seal the inlet 62, FIG. 4, but will move upwardly to openthe inlet in response to such inward flow of the refrigerant through thecompressor inlet 60, and into the chamber 43.

It should be understood that while a ball valve is used in the presentembodiment any valve member operating as a ball valve may be employedsuch as a plunger having spherical ends which would by gravity normallyremainin a closed position.

During initial gas flow the valve 64 assumes the position indicated bydotted lines in FIG. 4. However, during low pressure portion of thecompressor cycle the ball valve 64 by gravity moves away from the upperplate 28 and the following high pressure portion of the cycle causes theball valve to once again be driven against the upper plate 28. Duringthe high speed operation of the rotary compressor an objectionalclattering noise would result if the ball valve 64 were permitted .topulseagainst the plate 28 with the pulsing of the incoming gas.

Means are therefore provided in the present embodiment to hold the ballvalve 64 to prevent the objectional clattering and resultant wear duringthe operation of the compressor. To this end, as best seen in FIG. 4 theupper plate opposite the inlet 60 is provided with a recess or holdingarea 69 formed by a concave surface area being a substantially sphericalsegment 68 which in the present embodiment is substantiallycomplementary to the ball valve 64. However, as will be hereinafterexplained the precise shape and dimension including the surface area ofthe segment 68 may vary in accordance with other factors.

As is well known in the refrigerant art a small quantity of oil orlubricant is entrained in and carried throughout the refrigerant systemby the refrigerant. This small amount of oil which is mixed with therefrigerant gas is sufficient to cover the internal parts of thecompressor with a film of oil. Thus, the spherical surface area 68 ofthe holding area 69 is coated with a film of gas and lubricant which iseffective in providing enough surface tension to maintain the ball 64 inthe holding area 69 and in contact with the surface area 68 as shown indotted lines in FIG. 4 while the compressor 14 is operating andparticularly during the low pressure portion of the compressor cycle.The holding area 69 is dimensioned in combination with the particularball and oil used to accommodate both the ball 64 and the thickness ofthe film of oil. In effect, the ball 64 is maintained in the holdingarea 69 and against the surface area 68 during that time when the rotoris between points A and B as seen in FIG. 2 and there is very low flowof refrigerant or suction gas into the compression chamber 16. Whenoperation of the compressor terminates and the flow of suction gasterminates, the weight of the ball 64 is sufficient to break the surfacetension between the ball 64 and the surface 68 caused by the film of oiland the ball drops freely onto the valve seat 62 to prevent reverseflow.

While the suction valve embodying the present invention is shownincorporated within the cylinder housing of the compressor it should beunderstood the valve could be a separate component from the compressorand be inserted in the suction line of the refrigeration system.Accordingly referring now to FIG. 6, there is shown a second embodimentof the invention wherein parts identical to those of the embodiment ofFIGS. 1-5 are shown by the same numerals.

It should be apparent from the above description that the exactconfiguration of the parts must be determined for each specificapplication of the principles of the present invention. Morespecifically in carrying out the present invention it should beunderstood that the pressure of incoming refrigerant gas including thetype of refrigerant used, the size and weight of the ball valve 64, theexact surface area 68, dimensions or configuration of the holding area69, the type of lubricant and amount used, including the speed ofrotation of the compressor, are all factors in carrying out theteachings of the present invention. Since all of the above factors maybe variables, providing a ball valve 64 that is positively held in anopen position to prevent clattering during low refrigerant flow portionof the rotary compressor operation and for releasing the ball valve 64at predetermined time after termination of compressor operation toprevent reverse flow of refrigerant gas requires a certain amount ofexperimentation. Accordingly, the following list is intended to show theparameters used to carry out the present embodiment. It should beunderstood that in carrying out other embodiments such as the embodimentshown in FIG. 6 other parameters might be necessary.

VALVE 64 Weight 16.3 grams Dia. .625 VISCOSITY Oil & R22 S.U.S 50-100Oil S.U.S 200 GAS Type R22 Temp. 60F F Flow 250 370 Ib/hr Velocity 540ft/min 840 ft/min HOLDING AREA 69 Surface Area 68 .2474 in. Radius .315COMPRESSOR RPM 2.500 3,500 RPM In accordance with the present embodimentof the invention, retainer means 70 is provided in the inlet area 44which is effective in maintaining the ball valve 64 in verticalalignment between the inlet 60 and the holding area 66. As shown inFIGS. 2 and 4 and particularly FIG. 5, the retaining means 70 comprisesa body portion 72 formed to provide a cylindrical retaining area 74dimensioned to allow free vertical movement of the ball valve 64. Thebody portion 72 is provided with an open vertical area 76 through whichrefrigerant can communicate between the inlet 60 and the compressionchamber 16 when the ball valve 64 is in its open or up position. Inorder to secure and locate the retainer 70 in the inlet area 44, thefree ends of the body portion 72 adjacent the opening 76 are providedwith flanges 78 which slidably engage slots 80 (FIG. 2) formed in thehousing 18.

In addition to providing a means for retaining the ball valve 64 inproper vertical alignment between the valve seat 62 and the holding area66 the retainer 70 is generally constructed of a harder material thanthe housing 18 and thereby provides surface that is relatively lesssusceptible to wear by action of the ball valve 64. The retainer 70, ineffect, prevents the constant movement or pulsing of the valve 64 fromcausing particles of oxide to chip or flake off the cylinder.

The above feature of providing a relatively hard wear surface for theball valve 64 is important to the life of the compressor unit in thatparticles from the housing 18 that may be entrapped in the system cancause compressor failure.

It should be apparent to those skilled in the art that while what hasbeen described is considered at the present to be the preferredembodiment of this invention, in accordance with the Patent Statutes,changes may be made in the disclosed ball check valve without actuallydeparting from the true spirit and scope of this invention.

While there has been shown and described a specific embodiment of theinvention, it will be understood that it is not limited thereto and itis intended by the appended claims to cover all such modifications asfall within the true spirit and scope of the invention.

What is claimed is:

l. A rotary compressor comprising:

a cylindrical wall member and upper and lower end plate members definingan annular compression chamber for receiving a charge of refrigerant;

an inlet chamber in said cylindrical wall member extending between saidupper and lower end plates and communicating with said compressionchamber;

a suction port in said lower end plate including a valve seatcommunicating with said channel;

a valve member arranged for vertical movement in said inlet area betweensaid valve seat and said upper plate when a refrigerant charge isintroduced into said compression chamber during the operation of saidcompressor;

valve member holding means having a film of lubricant being formed insaid upper plate in communication with the upper extremities of saidinlet area for receiving a portion of said valve during operation ofsaid compressor; and

said valve member holding means having a predetermined surface arearelative to said portion of said valve member being dimensioned so thatthe surface tension of said lubricant between said valve and saidholding means surface area is sufficient to retain said valve in saidholding means during operation of said compressor and for releasing saidvalve to close against said valve seat when said compressor operationterminates.

2. A compressor as set forth in claim 1 wherein said valve member is aball valve and said holding means being a concave spherical segment.

3. A compressor as set forth in claim 2 wherein a retaining meansremovably secured in said channel means for holding said ball valve insaid channel means.

4. A compressor as set forth in claim 3 wherein said retaining meansbeing joined by an arcuate section to provide a circular guideway forsaid ball valve extending vertically substantially between said upperand lower plates.

5. A compressor as set forth in claim 4 wherein said retaining meanshaving radially projecting bars formed along the vertically disposedfree ends for engaging slots in said channel means for locating andremovably securing said retaining means in said channel means.

6. A suction valve comprising:

a valve chamber including an inlet port for receiving a flow of gas, avalve holding means having a predetermined surface area opposite theinlet port, and an outlet port intermediate the inlet port and hold ingsurface;

a valve member in the chamber operable in response to said gas flow forcarrying said valve member to engage said holding means, said valvemember having a surface thereof engaging the holding means surface areabeing shaped to be in substantial conformity with the configuration ofthe holding sur face;

means for providing a restoring force to urge the valve toward the inletport; and

a liquid film between the valve surface, and the hold ing means surfacearea, said liquid being of a viscosity sufficient to produce a surfacetension in relation to the degree of conforming engagement between thevalve surface and the holding means surface area to maintain said valvein contact with said holding means surface area and to overcome therestoring force for at least a predetermined amount of time.

7. A suction valve according to claim 6 wherein said liquid is a mixtureof refrigerant gas and lubricant.

=l l l

1. A rotary compressor comprising: a cylindrical wall member and upperand lower end plate members defining an annular compression chamber forreceiving a charge of refrigerant; an inlet chamber in said cylindricalwall member extending between said upper and lower end plates andcommunicating with said compression chamber; a suction port in saidlower end plate including a valve seat communicating with said channel;a valve member arranged for vertical movement in said inlet area betweensaid valve seat and said upper plate when a refrigerant charge isintroduced into said compression chamber during the operation of saidcompressor; valve member holding means having a film of lubricant beingformed in said upper plate in communication with the upper extremitiesof said inlet area for receiving a portion of said valve duringoperation of said compressor; and said valve member holding means havinga predetermined surface area relative to said portion of said valvemember being dimensioned so that the surface tension of said lubricantbetween said valve and said holding means surface area is sufficient toretain said valve in said holding means during operation of saidcompressor and for releasing said valve to close against said valve seatwhen said compressor operation terminates.
 2. A compressor as set forthin claim 1 wherein said valve member is a ball valve and said holdingmeans being a concave spherical segment.
 3. A compressor as set forth inclaim 2 wherein a retaining means removably secured in said channelmeans for holding said ball valve in said channel means.
 4. A compressoras set forth in claim 3 wherein said retaining means being joined by anarcuate section to provide a circular guideway for said ball valveextending vertically substantially between said upper and lower plates.5. A compressor as set forth in claim 4 wherein said retaining meanshaving radially projecting bars formed along the vertically disposedfree ends for engaging slots in said channel means for locating andremovably securing said retaining means in said channel means.
 6. Asuction valve comprising: a valve chamber including an inlet port forreceiving a flow of gas, a valve holding means having a predeterminedsurface area opposite the inlet port, and an outlet port intermediatethe inlet port and holding surface; a valve member in the chamberoperable in response to said gas flow for carrying said valve member toengage said holding means, said valve member having a surface thereofengaging the holding means surface area being shaped to be insubstantial conformity with the configuration of the holding surface;means for providing a restoring force to urge the valve toward the inletport; and a liquid film between the valve surface, and the holding meanssurface area, said liquid being of a viscosity sufficient to produce asurface tension in relation to the degree of conforming engagementbetween the valve surface and the holding means surface area to maintainsaid valve in contact with said holding means surface area and toovercome the restoring force for at least a predetermined amount oftime.
 7. A suction valve according to claim 6 wherein said liquid is amixture of refrigerant gas and lubricant.